The proposed research has two aims: It investigates the nature of phonological competence and examines its role in reading skill. To address the nature of phonological competence, we identify three sets of core phonological preferences that linguistic analysis suggests are universal. The proposed research examines whether speakers exhibit such preferences, investigates the nature of experience required for their emergence (including the statistical properties of linguistic input and its richness in acoustic and articulatory detail), and tracks their developmental onset in infancy. The second goal of the proposal is to examine the role of phonological competence in reading skill. Although it is well known that reading skilled hinges on phonological processing, the precise role of phonological competence in reading is not well-understood: Is the role of linguistic competence limited to early stage of reading acquisition (i.e., the development of phonemic awareness) or does linguistic competence interacts on-line in the representation of print in skilled reading? To address this question, the proposed research examines whether the representation assembled in silent reading is constrained by phonological markedness preferences and compares their structure to the representation of spoken language. The nature of core phonological constraints is a question that is central for linguistic theory and psycholinguistic research. Identifying the scope of core phonological preferences and their learnability from experience informs the study brain plasticity and illuminates the heritability of higher-order cognition, issues that are at the forefront of cognitive neuroscience and developmental psychobiology. Although the present research does not specifically address dyslexia, its outcomes are potentially relevant for the diagnosis an understanding of this reading disorder. In view of the high incidence rate of dyslexia in the population, the study of reading skill and reading disabilities also carries direct implications for human health.